Chord Mojo(1) DAC-amp ☆★►FAQ in 3rd post!◄★☆

[Blasyrkh]

   
It might be the end for you, but your facts apply to you, that doesn't mean others feel the same way. Mojo (in my experience) absolutely does NOT suck when playing from my Android phones. End of my story.

 
sure, it's all IMHO

 

[Carl6868]

  Hi, I've just bought a Mojo which I'm running with an iPhone 6S and the ONKYO HF Player. I've gone the AK100, AK100II, AK120II, ZX1, ZX2 route, and this sounds, to my ears at least, far superior to all of them
 
Is there any particular advantage to turn up-sampling ON or OFF in HF Player? For example would up-sampling reduce the Moho battery life? In general what advantages would up-sampling from, say 44.1 kHz, have?
 
Thanks for any advice

 
You want to switch up-sampling off and send the music to the mojo in its native rate.

 

[Joe Bloggs]

Ok, i tested again a Note 3 and S6 phones....

S6 has a native support, note 3 does not. both Lollipop

problems are still there,for both phones, there's a subtle distortion, clicks and pops during playback, but even in background
with mate 7 distortion is much more hearable, so that should be a phone problem.

Anyway, mojo is definately NOT and android phone friendly DAC.
even my DAC1 of many years old can work with android, that doesn't mean it's an android dac.

just making more tests, the Fiio E18 pc mode out works with the otg adapter, but not with the included micro to micro cable.
this means 2 things:

E18 micro to micro cables are not really otg cables, or are made to work with fiio E18 phone mode only.

then, MOJO is just an USB DAC made for pc, with wanna be android compatibility mode, and that means it draws power from battery phone or it's prone to noise .
it may be prone to glitches, even very very subtle glitces, difficult to hear when on the go and without a carefull listening session.

with galaxy S6 and a longer cable and airplane mode, glitches and digital noise are still really subtlelty hearable, and accurately comparing the sound quality when connected to pc, it's evident.
with pc the mojo is smoother and better sounding. and it is a funny finding knowing that it is not galvanically isolated.

fiio E18 is really an android/mobile dac and well engeneered for portable use with USB devices.

MOJO is not, and it sucks when usb connected to phones.
that's the end of the story

As FiiO's rep, I could just thank you for your compliment of the E18 But actually, you're right--the micro-micro USB cables that came with the E18 are only meant to be used with the E18 in (smart)phone mode, as it had OTG circuitry built in in that switch position. But that's not how most portable DACs do things these days (although the E18 in phone mode should also be compatible with OTG cables)--our newer DACs just incorporate a standard micro USB port (so you would use an OTG cable to connect), having a separate menu setting or power switch to enable or disable charging from the USB port.

So if I read right, you've moved beyond trying the E18's cable with the Mojo to using other OTG cables for the connection, so that shouldn't be the problem, right? Moving on--your talk of "subtle digital noise" and me digging around looking for build.prop info on the Galaxy S6 has me smelling a fish.

Here's a test for you to try:
https://www.dropbox.com/s/abnqmqvlj94r5lx/44.1kHz%200.8%20sweep%20linear.flac?dl=0
https://www.dropbox.com/s/wvgmomwrcc6yosh/48kHz%200.8%20sweep%20linear.flac?dl=0

Try downloading these two files and playing them on your phones. Try it with and without the mojo (i.e. directly out the phone's headphone out). For this test I would try using Poweramp as the player and disable its "Direct Volume Control"--this way you're deferring everything to the stock Android sound system.

These two files should sound the same--they're tone sweeps from 0 to 22 or 24kHz. If instead you hear warbling over/undertones with one of the two files, then you have caught the fish I was smelling--a very old fish that shouldn't be in the pond of smartphones anymore in this day and age, but who knows :rolleyes:

As for why the Mojo and not the E18 is not prone to it--if the issue is indeed the one I'm suspecting--you would need to read out the sampling rate light color on the Mojo while playing each of the file I gave you, and which one is giving the sonic problems. I should clarify at this point that the problem I suspect has everything to do with the smartphones and nothing to do with the Mojo. h34r:

 

[Mython]

  Hi, I've just bought a Mojo which I'm running with an iPhone 6S and the ONKYO HF Player. I've gone the AK100, AK100II, AK120II, ZX1, ZX2 route, and this sounds, to my ears at least, far superior to all of them
 
Is there any particular advantage to turn up-sampling ON or OFF in HF Player? For example would up-sampling reduce the Moho battery life? In general what advantages would up-sampling from, say 44.1 kHz, have?
 
Thanks for any advice

 
Here's what Mojos designer had to say on the topic:
 
 

  Converting the original file into DSD or up-sampling is a very bad idea. The rule of thumb is to always maintain the original data as Mojo's processing power is way more complex and capable than any PC or mobile device.
 
DSD as a format has major problems with it; in particular it has two major and serious flaws:
 
1. Timing. The noise shapers used with DSD have severe timing errors. You can see this easily using Verilog simulations. If you use a step change transient (op is zero, then goes high) with a large signal, then do the same with a small signal, then you get major differences in the analogue output - the large signal has no delay, the small signal has a much larger delay. This is simply due to the noise shaper requiring time for the internal integrators to respond to the error. This amplitude related timing error is of the order of micro seconds and is very audible. Whenever there is a timing inaccuracy, the brain has problems making sense of the sound, and perceives the timing error has a softness to the transient; in short timing errors screw up the ability to hear the starting and stopping of notes.
 
2. Small signal accuracy. Noise shapers have problems with very small signals in that the 64 times 1 bit output (DSD 64) does not have enough innate resolution to accurately resolve small signals. What happens when small signals are not properly reproduced? You get a big degradation in the ability to perceive depth information, and this makes the sound flat with no layering of instruments in space. Now there is no limit to how accurate the noise shaper needs to be; with the noise shaper that is with Mojo I have 1000 times more small signal resolution than conventional DAC's - and against DSD 64 its 10,000 times more resolving power. This is why some many users have reported that Mojo has so much better space and sounds more 3D with better layering - and its mostly down to the resolving power of the pulse array noise shaper. This problem of depth perception is unlimited in the sense that to perfectly reproduce depth you need no limit to the resolving power of the noise shaper. 
 
So if you take a PCM signal and convert it to DSD you hear two problems - a softness to the sound, as you can no longer perceive the starting and stopping of notes; and a very flat sound-stage with no layering as the small signals are not reproduced accurately enough, so the brain can't use the very small signals that are used to give depth perception.
 
The second issue in using the transport to up-sample (44.1 to 176.4 say) is that the up-samplers in a PC or mobile device are very crude, with very limited processing power and poor algorithms. This results in timing problems, and like with DSD you can't hear the starting and stopping of notes correctly. These timing problems also screw up the perception of timbre (how bright or dark instruments sound), the pitch reproduction of bass (starting transients of bass lets you follow the bass tune), and of course stereo imagery (left right placement is handled by the brain using timing differences from the ears). Now Mojo has a very advanced algorithm (WTA) that is designed to maximise timing reconstruction (the missing timing information from one sample to the next) and huge processing power to more accurately calculate what the original analogue values are from one sample to the next. Its got 500 times more processing power than normal, and this allows much more accurate reconstruction of the original analogue signal.
 
So the long and the short is don't let the source mess with the signal (except perhaps with a good EQ program) and let Mojo deal with the original data, as Mojo is way more capable.
 
Rob

 

[ClieOS]

   
wrong
 
neutron works very well with Fiio E18 in direct mode.
 
with mate 7 i own it only works in direct mode because it has not a native support.
 
anyway, with mate7+ mojo i don't have any kind of fast forward like in UAPP...did you try changind the reproduction speed to see if it works?

 
You are right, somewhat. I hadn't tested the USB DAC function on the latest Neutron build and I just did  - E18 does work now, so is the newer FiiO Q1. But it is still somewhat problematic with Oppo HA-2 where the DAC/amp can get disconnect randomly, but it is not frequent. Mojo still doesn't work, so is iFi micro iDSD. To be fair, I have no problem with any of them with any of the other apps I used, including Sony Music apps (native USB support with upsampling), UAPP or Onkyo - so I'll still call Neutron's USB DAC function to be somewhat broken. In fact, trying to connect micro iDSD with Neutron in USB mode almost bricks my Xperia Z3+. I have to do a hard rest to get my smartphone's control back.
 
p/s: it is rather scary that a music app can malfunction to a point of almost bricking a smartphone.

 

[Blasyrkh]

As FiiO's rep, I could just thank you for your compliment of the E18

But actually, you're right--the micro-micro USB cables that came with the E18 are only meant to be used with the E18 in (smart)phone mode, as it had OTG circuitry built in in that switch position. But that's not how most portable DACs do things these days (although the E18 in phone mode should also be compatible with OTG cables)--our newer DACs just incorporate a standard micro USB port (so you would use an OTG cable to connect), having a separate menu setting or power switch to enable or disable charging from the USB port.

So if I read right, you've moved beyond trying the E18's cable with the Mojo to using other OTG cables for the connection, so that shouldn't be the problem, right? Moving on--your talk of "subtle digital noise" and me digging around looking for build.prop info on the Galaxy S6 has me smelling a fish.

Here's a test for you to try:
https://www.dropbox.com/s/abnqmqvlj94r5lx/44.1kHz%200.8%20sweep%20linear.flac?dl=0
https://www.dropbox.com/s/wvgmomwrcc6yosh/48kHz%200.8%20sweep%20linear.flac?dl=0

Try downloading these two files and playing them on your phones. Try it with and without the mojo (i.e. directly out the phone's headphone out). For this test I would try using Poweramp as the player and disable its "Direct Volume Control"--this way you're deferring everything to the stock Android sound system.

These two files should sound the same--they're tone sweeps from 0 to 22 or 24kHz. If instead you hear warbling over/undertones with one of the two files, then you have caught the fish I was smelling--a very old fish that shouldn't be in the pond of smartphones anymore in this day and age, but who knows

As for why the Mojo and not the E18 is not prone to it--if the issue is indeed the one I'm suspecting--you would need to read out the sampling rate light color on the Mojo while playing each of the file I gave you, and which one is giving the sonic problems. I should clarify at this point that the problem I suspect has everything to do with the smartphones and nothing to do with the Mojo.

 
Hi Joe, thanks for the answer
 
sadly the samsung s6 and note 3 aren't mine, but  coworkers'
i can ask to use them tomorrow at least.
 
do you think the problem is the sampling frequency?
consider that i used a direct usb out with hiby music, so android output should be totally bypassed
another thing i would like to clear out, is that with note 3 and s6 the digital noise is really subtle, while with my mate 7 is much more evident.
this just to be sure to make the right troubleshooting.
 
that said, is there a test i can make with my mate7 to understand why the hell it generates so much noise?
it doesn't play usb audio natively.

 

[Joe Bloggs]

that said, is there a test i can make with my mate7 to understand why the hell it generates so much noise?
it doesn't play usb audio natively.

You could play the two files using poweramp and listen to them using the smartphone's headphone out, and then play them using UAPP and listen using the Mojo? Closest thing to what I intended.

 

[Blasyrkh]

   Mojo still doesn't work, so is iFi micro iDSD. 
 
 

 
that's strange, my mojo works with it, without any issue exept for the common distortion

 

[ClieOS]

   
that's strange, my mojo works with it, without any issue exept for the common distortion

 
Every time I tried to play something, Mojo's power light will start cycling through all the colors as if it is resetting itself. I am not going to do more test on Neutron for the moment as I don't want to almost brick my smartphone twice in a day.

 

[rkt31]

so mojo is better than schiit bifrost and gungnir . what about yggy ? has anybody tried feeding a headphone amp by mojo and yggy ? I believe mojo should beat yggy at 1/6th price .

 

[Blasyrkh]

You could play the two files using poweramp and listen to them using the smartphone's headphone out, and then play them using UAPP and listen using the Mojo? Closest thing to what I intended.

 
 
i tried, with mojo the colors matched the sampling freq. and where distorted as the music
 
with headphones out, from a fast listening, i can't hear any kind of distortion or background noise

 

[Joe Bloggs]

You could play the two files using poweramp and listen to them using the smartphone's headphone out, and then play them using UAPP and listen using the Mojo? Closest thing to what I intended.

i tried, with mojo the colors matched the sampling freq. and where distorted as the music

with headphones out, from a fast listening, i can't hear any kind of distortion or background noise

Then I guess it's not what I think it is That's as far as I would go speculating with some other brand's product's problems. Back to Chord support you go

 

[Blasyrkh]

Then I guess it's not what I think it is

That's as far as I would go speculating with some other brand's product's problems. Back to Chord support you go

 
too bad
actually chord support is useless since they haven't answered at all after my question about distortion

 

[Layman1]

   
too bad
actually chord support is useless since they haven't answered at all after my question about distortion

Dude.. Come on.. You've made a lot of posts, and it's great that you're providing lots of info to the thread and asking around for solutions.
But..
"Mojo.. sucks when usb connected to phones" and "Chord support is useless".. Such dogmatic statements only alienate others and cause argument.
 
All you have to say is like "I don't know why, but Mojo always sucks for me when usb connected to phones" or "Chord support haven't addressed my question; I'm disappointed, especially considering I've spent $700 on this" (or whatever you've spent lol).
 
The second set of comments would invite sympathy, and suggested solutions. The first set of comments would tend to invite argument or negative feelings..
You've clearly got useful and positive info and ideas to share, just hope this can help to make it more, erm, easily digestible

 

[Blasyrkh]

thanks to have underlined that, i'll try to be more...polite then
 
actually i had lots of expectations...considering that e18 and DAC1 worked like a charm, it's sad to see that a theorically portable device is having problems with an OS that should be supported.
And after i spent, as you stated, 600€, i would like to have support from them...we will se if they'll answer in the future.
 
but if i must be fair, i have to say that even huawei sucks at usb audio compatibility, because it has the noisier usb port i tested
 
 
back to the problem, it would be really interesting to understand theroot of the problem, explained by a mojo engeneer.